In 1933, the Bible School began offering a four-year ThB (Bachelor of Theology), which expanded to a five-year course in 1942.

The Witmarsum school closed in 1931 for what was assumed to be a year or two during which a better location could be found and an association with an older seminary arranged.

Mennonite Biblical Seminary was opened in September 1945 and used available space at Bethany for classes and student housing.

By the fall of 1946 the seminary purchased property on the 4600 block of Woodlawn Avenue as it prepared for more students who were expected with the end of Civilian Public Service.

[3] Each year about a dozen Mennonite students who were attending other Chicago schools were allowed to use Seminary apartments.

In 1953, MBS worked together with Goshen Biblical Seminary to create a joint summer school for the following year.

This process was culminated in 1958 by which time the Chicago property had been sold and the Seminary moved to a new joint campus in Indiana.

Over the years closer cooperation eventually eliminated the distinction between the two schools, and by 1994 they formally merged into the (now-singular) Associated Mennonite Biblical Seminary.

By 2002 the two Mennonite denominations themselves had joined to form a common structure, in which decades of cooperation between the two groups at AMBS had played a role.

[7] The Institute has fostered inter-Mennonite connections and scholarship advances in the areas of Anabaptist theology and history since 1958.

The library construction included the installation of a "green landscape," including rain gardens surrounding most of the library's exterior and a prairie restoration project that restored significant portions of the campus ground to its original tall-grass prairie.